Epidermoid Carcinomas of Esophagus and Forestomach Induced in Syrian Hamsters by N-Nitroso-N-Methylurethan

Publisher Website
Google Scholar
Abstract
The effect of intragastric administration of N-nitroso-N-methylurethan was studied in Syrian hamsters. All animals developed epidermoid carcinomas of the forestomach which locally invaded the peritoneum, liver, and diaphragm. Thirteen of the 16 animals had epidermoid carcinomas of the esophagus. The malignant tumors were multicentric in origin. In addition to the tumors, the entire surface epithelium of the esophagus and forestomach revealed diffuse histopathological changes including hyperkeratosis, basal-cell hyperplasia, epithelial atypism, and papillomas. These findings indicate that the mode of action of N-nitroso-N-methylurethan is not local. A few of the animals revealed thecomas of the ovary, papillomas of the vagina, and stromal hyperplasia of the endometrium. The significance of these lesions is not known. When compared with the effects of N-nitroso-N-methylurea in Syrian hamsters, the finding suggests that though there are decided differences in the local effect of these two carcinogens, there may be similarities in regard to the metabolic pathway and metabolites formed by them.